This analysis will likely be seen as a bit of grave-dancing on my part, given that I have been an occasional target of the wrath of Kos. But while I am troubled by their hostile, hyper-partisan tendencies, I think the Kossacks have at their best made enormous contributions to the party over the last few years -- most noticeably by stiffening the Washington establishment's spine in confronting President Bush and energizing and organizing the base. One could credibly argue, in fact, that Mr. Obama would not be in the position to inspire the base if Kos and his allies had not first helped to get them "fired up, ready to go."

In this, you might say that Mr. Obama did not kill Kos-ism so much as co-opt it -- by harnessing its most powerful forces and channeling it in a more constructive, convincing direction for a new political moment. He recognized early on that the primary electorate was changing in the wake of Mr. Bush's departure, and that it was hungry (post-Boomer voters in particular) for something bigger and better than the same polarization wrapped in a blue ribbon.

The signs of change are unmistakable. Over the last year, the Kossacks themselves seemed to be waning -- the number of monthly page views on the site is down dramatically.

Moreover, in the last few weeks they and their avatars have been flocking to the great reconciler. First Ned Lamont endorsed Mr. Obama, a mentee of Mr. Lieberman in the Senate. Then on Wednesday, in the first Daily Kos straw poll after Mr. Edwards left the race, Mr. Obama beat Mrs. Clinton by 76%-11% (a result inflated by the Netroots' unbreakable contempt for Hillary). Just yesterday, MoveOn.org gave its formal blessing to the "post-partisan" candidate.

The best evidence that Kos-ism is about kaput, though, comes from Kos's mouth himself. Yes, the most delicious irony of this campaign is that the supposed hatemonger is supporting the hopemonger.

Seeing the writing on the wall, as well as on his own blog, Markos Moulitsas -- Kos himself -- rejected the candidacy he himself helped spawn and announced (albeit grudgingly) on Dec. 12 that he would be voting for Mr. Obama via "a process of elimination."

Not exactly the most graceful concession, but the import is undeniable: Hope trumped Kos for Democrats. Now let's see what it will do for the rest of the country.